As an example, the IoT Gateway provides a code visualization of Graphviz diagram code. Instead of presenting the actual code, the code is converted to an image, and the image is presented. This requires Graphviz to be installed on the machine. The following example is taken from the Graphviz reference documentation. The following diagram shows how the code is presented in the rendered HTML output:

```dot: Fancy graph 
digraph G {  
   size ="4,4";  
   main [shape=box]; /* this is a comment */  
   main -> parse [weight=8];  
   parse -> execute;  
   main -> init [style=dotted];  
   main -> cleanup;  
   execute -> { make_string; printf}  
   init -> make_string;  
   edge [color=red]; // so is this  
   main -> printf [style=bold,label="100 times"];  
   make_string [label="make anstring"];  
   node [shape=box,style=filled,color=".7 .3 1.0"];  
   execute -> compare;  
} 
```